Process of producing pure turpentine.



T. W. PRITGHARD. PROCESS OF PRODUCING PURE TURPENTINH' APPL IGA TION FILED SEPT 3,1912,

Patented Sept. 15, 1914.

1,1 1&819,

lZ/VVE/VTOR v a Wa W4 entrain sit-AT .ATENT @JHFTCE I THOMAS WILLIAMS PR'I'rcHARn, or WILMINGTON, NORTH CAROLINA.

PROCESS F PRODUCING EUBE EURPENTINFL To all whom it may concern:

Be it known that I, THOMAS PnrrcH- Ann, a citizen of the United States, residing at" Wilmington, in the county of New Han over, State of North Carolina, have inventf ed-certain new and useful Improvements in Processes of Producing Pure Turpentine, of which the following is adescription, refer; ence being had to the accompanying draws ings, forming a part hereof.

My invention relates to/a process of refin: ing turpentine, particularly that produced from treating the resinous wood bydistillai tion, either destructive or otherwise, and has for its object the elimination of objecf tionabletmatter commonly found to bepres ent in turpentine so produced by which its market value is lessened as compared with turpentine produced from the sap drawn from the tree by tapping.

In the production of turpentine from the wood itself by the application of heat either directly to the wood as by a bath of heated material or in the ordinary process of dis tillation either destructive or otherwise by the application'of heat to a retort in which the wood is contained, it is'found that more or less pine oil 'of somewhat greater vis-l cosity than the turpentine is mixed with the turpentine and cannot be eliminated by re-' distillation. It is also found that almost always turpentine so produced from wood is characterized by odors which are more or less olfenslve and distinguish 1t on the mar-' ket from the turpentine produced from the sap of the pine.v These offensive odors are due either to aldehydes, which are more highly volatile than the turpentine, or to Referring to the drawings Figure 1 is an elevation partly in section of an apparatus adapted to be used to carry out my process; and, Fig. 2 is a cross sectional view on lin a-a of Fig. 1. 1

Specification (if Letters Patent. lPatent edl Sept. 15, 1914i. Application filed September ,3, 1912. Serial N ol-'718,435 I In the drawings, which are to be understood as illustrative merely and not intended to limit the invention to the use of theapparatus shown, or any particular construction or arrangement of apparatus, 1 is a tank or retort adapted to cOntain" the turpentine to be treated. Within this tank is preferably arranged'a heating coil 2. In the tank near its bottom s arranged an air pipe 3, pro- .vided with numerous perforations, the pipe extending acrossthe tank and communicating at its ends with vertical air inlet pipes i open at their upper ends. A draw ofi' pipe 5 leads from the bottom of the tank. In the top of the tank is an opening for the escape of the vapors hereinafter described, which opening is covered on the interior of they leads outlet pipe 14. Surrounding the tank and extending considerably above half its height is an outer tank or bath 12 between which and the tank 1' the branch steam or hot Water pipe extends, the vertical air inlet pipes 4 being also between thetank 1 and the tank 12. Outlet 13 leads from the tank 12.

In the top of the tank 1 is an inlet opening 8 by which the turpentine to be treated may be introduced into the tank. Over the opening for the escape of the vaporized turpentine is a hood 9, from which delivery pipe 15 leads to a worm 17 in a tank 16- having overflow 18. From the lower end of the worm 17 leads pipe 19 with which one end of a transparent tube 20 is connected, the other end of the transparent tube being connected to a pipe leading to a tank at a point near its top, this pipe having therein a valve 21 and having a valved branch pipe 22 leading from it at a point between the transparent ,tube and the valve 21. VVithin the tank 23 opposite the end of the pipe into which the transparent pipe 20 leads is a baffle plate 24:.

Leading from the bottom of the tank 23 is. a drawoif pipe 26. From the tank near its upper end leads a pipe 27, suitable baffle plates 25 being arranged within the tank opposite the inner end of this pipe. The

-' outer end .ofithis pipe 27 .isconnected with an injector orjet pump having inlet pipe 29 leading from any. suitable water supply and having discharge pipe 30.

A gage'class 31 on one side of tank 23 servesto showthe level of the liquid in it. In.- its tophthe tank 23. is provided with a manhole 320i usual construction.-

In operationthe tank 1 is partly filled with the turpentine to' be treated and the bath 12 is filled with hot water through the branch pipe 10 if the pipe 11 is used to supply hot water, or the bath may be otherwise .filled with water and the water heated by steam from branch pipe 10 if the pipe 11 is supplied with steam. Hot water or steam, as the case ma be, is supplied to the heating coil by the pipe 11. If steam is used it should be wet steam, that is steam at a temperature not much above 212 degrees F the purpose of the heat supplied by the water in the tank 12 and the steam orwater in the heating coil 2 being to warm the turpentine to be treated to about 212 degrees F. and maintain it Iat'this temperature without heating it to a temperature at which it would boil, or be vaporized by heat and be the tank 12 to a temperature not exceeding distilled over.

On starting the injector or jet pump 28 a partial vacuumwill be created in the-tank 23, the worm 17, delivery pipe 15 and tank 1 and air will enter through the vertical pipes 4 and perforated pipes 3 to relieve this partial vacuum, the air so entering being heated in the vertical pipes 4 by the hot Water in the temperature of the Water which as above stated is not above 212 F.,'and being discharged through the perforations in the pipes 3 will bubble up through the turpentine inthe tank. A. current of warm airwill thus be established, the air being drawn through the turpentine not forced into it.

The turpentine being warmed is sutliciently lightened to be carried over by this current of warm air I while the pine oil having greater vapor tensionthan the turpentine will not be carried over but will be left in the tank '1, and the vapor thus formed will pass out through the hood 9 and delivery pipe 15 into the worm 17 Where it'will condense and flow through pipes 19 and 20 into I tank 23. The aldehydes carrying objectionable odors if present will probably not condense and if they do not they will pass oif through the injector jet pump 28. As they are more volatile than the turpentine they will, if condensable, come through the worm at the. beginning of the run and may be drawn off through the branch pi e 22. The

empyreumatic oils carrying o jectionable odors being more viscous than the turpentine will remain in tank 1 with the pine oil. The shield 6 prevents any of the pine oil which may be carried up by the air currents irom being carried into the delivery pipe 15. By thus drawing the warm air in minute streams or bubbles through the warm turpentine more or less oxidation of the aldehydes takes place.'" As a result of the operation of the process as thus described a pure turpentine is produced freed from' pine oil 7 and freed from objectionable odor, identical in appearance, in odor and in all other respects with the turpentine produced from sap. p

Having thus described my invention what I claim is: p

1. The herein described process of producing pure turpentine by distillation of turpentine containing impurities which consists in drawing through it air warmed to a temperature not substantially above 212 F.

drawing through it air heated to a temper- Q ature not substantially above 212 FL, and condensing the vapors carried ofi wlth the This specification signed and witnessed this 30th day of August, A. D. 1912.

THOMAS WILLIAMS PRI'IOHABD.

In the presence of J. G. THORNTON, J. L. WILLIAMS. 

